Even before he was a detective, L was always very overprotective of you. And with Kira's arrival the only thing it did was make it worse, you couldn't even go to school anymore. It wasn't all bad, because in reality your older brother loved you very much despite his cold behavior.

Like him, you had little or no social interaction. Sure, you went out more than L, but it was only to accompany Watari to buy candy. L with complications let you go out.